Most output from photocomposition machines has been on wet process photographic paper. Photocomposition is undoubtedly the biggest use of encoded output medium in the business machine classification, and hence is used as an illustration of the invention.
The standard procedure has been to collect the exposed photographic film or paper in a light-tight cassette removably attached to the photocomposition machine, and the cassette physically transported to a separate developing machine where the paper is fed through a light-tight junction box from the cassette into the developer.
Dry process papers have been known for some period of time, but have never been widely adopted for photocomposition use until very recently. U.S. Pat. No. 3,457,075 illustrates the state of this art. Such dry silver papers are heat developed and are of good technical quality. Because there are no chemicals used to develop the dry silver paper, but rather the paper being developed solely by the application of measured amounts of heat, there is no necessity to separate the paper in the cassette from the production phototypesetter. However, the output from the phototypesetter is considerably slower than the speed at which the paper must be processed through a heat developer. Hence, it has been thought necessary to collect the paper and separately develop as done with the chemical processing papers.